Rapid salvage system for submarines



Dec. 17, 1929? 1 s 1,740,231

RAPID SALVAGE SYSTEM FOR SUBMARINES Filed NOV. 12, 1928 4 Sheets-$heet ll'mventor Edward Bash-7:9

attorneys.

Dec. 17, 1929. E. ELLSBERG 1,740,231

RAPID SALVAGE SYSTEM FOR SUBMARINES Filed Nov. 12, 1928 4 Sheets-Sheet 2Emmi M955? 'ZJZZkM rm Dec. 17, 1929. E. ELLSBERG 1,740,231

RAPID SALVAGE SYSTEM FOR susmmmas Filed Nov. 12, 1928 4 Sheet s-Sheet 3attorn egs.

Dec. 17, 1929. E. ELLSBERG RAPID SALVAGE SYSTEM FOR SUBMARINES FiledNov. 12, 1928 4 Sheets-Sheet 4 Edward E 15566;; or

attorneys.

Patented Dec. 17, 1929 EDWARD ELLSBEBG', OF WES'EFIELD; NEW JERSEY RAPIDSALVAGE SYSTEM- FOR"SUBMAR1NES' Application filed November 12", 1928,Serial No, 31 8;921.

My invei'it'io'n relatesto salvaging apparatus for use ini-aisingj'sunken vessels, and is especially adapted to raise sunkensubmarines. v I

It is weltknown that the hull of submarines are particularly vulnerablewhen struck by solid Objects, and that the wounds caused by collisionshave frequently caused a submarine to sink quickly carryin with her allthe crew, or such of those not able to escape, v

Such members of the crew as are inrp'rison'ed in water tightcompartments may exist for a limited time, but unless speedy suc- '5corisgiven, these imprisoned persons willinevitabiy succumb; andtherefore, with submarines, it is especially desirable that salvagingapparatus may be available, which may be quickly and successfullyoperated to bring the unken vessel to the surface.

In methods hitherto adopted, insalvaging submarines, it has been thepracticeto pass chains under the sunken vessel, but this is'a tediousoperation, and can only be effectedby divers tunnelling in the mud, oozeand other materials at the bottom of the ocean, and this operation isattended with special difficulty when the water is deep, or when itssurface is rough; It frequently happens that such 3 tunnelling isimpracticable, and it is a part of m'y invention to provide'apparatusthat willobviate the necessityofany such tunnelling, 1

Again in raising sunken vessels, it is :55 usually ound necessary toemploy pontoons,

which are difficult to control, especially in a rough sea, and whoseoperation frequently causes serious if not fatal, delays-in thesalvagingi operations,

The difficulties hitherto experienced, and the methods proposed bym'efor impr vin those: conditions and in secu'ring rapid and effectiveoperation of the salvaging system will be hereinafterrno'r'e' fullyexlained, and illu tratedin: the drawings.

For the rapid salva "e and rescue of sunken submarine boats and 1; "enerews,-- all pr vious methods have proven slow" or impracticable There"has not. hitherto existed any rapid and sure means of attaching liftinggear" to" submarines, nor reliable and safe means of liftingunderconditions of open sea work.

Derricks have been used on small submarines in shallow water in aharbor, hooked to eyes worked into the bow and stern of small submarines(under about three hundred tons) for larger submarines such eyes at thebow and stern are impracticable as they cannot be' made strong enough tocarry half the weight of the submarine, nor can lifting gear of suchstrength be conveniently pro-- vided, nor can derricks having the powerto lift over one hundred fifty tons conveniently be found.

As a consequence, it has usually been neces sary at great expense,danger, and delay to dig tunnels underneath the sunken submarine, topass chains or slings under her for lifting, which is a processsometimes requiring months of work, and consequently is useless to savelife. It has also been proposed to drillholes, or burn holes, or punchholes, or by other means, make holes in the sides of sunken vessels tosecure lifting hooks or other attachments to the sides of submarinesalready sunk; but such proposals overlook the mechanical difliculties ofproviding the holes quickly, and the further di-fi'iculty that the sidesand structure of the submarine are so light that any such hooks orattachments to holes or bolts fastened to the sunken submarine Will tearout andbe unable to stand the strains of the necessary lifting forcesfor practical work.

It is, therefore, proposed that each submarine, as a part ofher hull, befitted with a set of lifting eyes, or attachments, which shallpermanently be secured to her hull in rows along each side, and sospaced and proportioned to take the lifting chains or wires from thespecial submersible stabilized pontoons, Whichare provided for thelifting means.

By using submersible stabilized pontoons of the design proposed, itbecomes possible to so reduce the strain which each lifting wire orchain must take, as to make it feasible without up due weight or bulktov provide on the submarines hull eyes or attachments which will takethe pull and not interfere with the normal operation oft-he submarine oradd a prohibitive weight to its displacement; the eyes being so smallthat they can be attached to the structure along the outside of the hullregistering with existing frames and bulkheads, where they areaccessible to divers, and to which the hoisting lines or cables can beconveniently attached.

To this end it is proposed that, for submarines of about one thousandtons, more or less, a series of twelve such eyes be secured along eachside, spaced in pairs, with about sixteen feet between the eyes in eachpair in the fore and aft direction, and with one such pair for abouteach forty feet of length. For other sizes of boats, the number of eyesshould be in proportion.

The eyes should preferably be just above the point of maximum width ofhull at each section, and for the ordinary type of submarineconstruction just above the watertight fiat over the ballast tanks inthe double hull part of the boat. It is-estimated that for the ordinaryboat, a pull of forty tons will be exerted on each eye by its pontoonchain or wire, and that for this pull, the eye and its attachments willweigh about two hundred pounds. For very large and wide boats, a thirdrow-of eyes may be added along the upper center line in the deck.

By this means, when a submarine sinks in any depth of water where diverscan work, it becomes possible speedily to shackle or otherwise secure tothe eyes or attachments on the submarine, the necessary lines, as Wiresor chains for lifting. The eyes being well up on the hull are accessibleto divers regardless of the list of the submarine, and the chains orattachments lowered from the surface can quickly be secured by thedivers without the need or delay of digging tunnels or drilling holes orendeavoring under water to make fast means for attaching lifting lines.It thus results that such chains or wires as will stand working strainsof about forty tons, which are the ordinary equip ment of vessels andshipyards, available for lifting. It further results that there is nodanger of the chains slipping along or out from under the hull, asoccurs when they are passed underneath the keel by the methodsheretofore employed, nor are the chains or wires liable to be cut orchafed in two by the keel as has frequently happened when used under thekeel as in previous practice.

Furthermore, the provision of eyes along the sides gives opportunity toexert a strong rolling movement to a submarine by exerting a pullinitially on one side only, thereby tending to move the submarine in herbed and break loose the suction effect, which is necessary in many casesbefore a submarine can by anypower be torn free from the bottom.

For use in connection with the novel system of eyes mentioned above,there is necessary a readily available lifting means. Derricks are notpowerful enough nor can they operate in the open sea. Salvage ships ofvarious forms have been proposed and built, but the technicaldifficulties of their operation has hitherto prevented success inlifting large submarines in the open sea.

Submersible i pontoons have heretofore been used with success for deepwater salvage, but I have found that pontoons of the type known to theprior art are unsafe to handle, and slow and difficult tolower intoposition properly, besides losing a considerable part of their liftingpower at the time when most needed. I have, therefore, invented for usewith my novel method of attachment, a novel submersible stabilizedpontoon which avoids the difficulties previously obtained.

Of the available lifting power of a pontoon, represented by its interiorvolume or displacement, part is required to overcome the weight of thepontoon itself, and the remainder only is the net lifting force.

'Io sink the pontoon, it must be flooded to a volume equal to its netlift, and it will then start to sink, leaving a space filled with air,which is equal in displacement to the weight of the pontoon itself,about forty tons for a large sized pontoon. ater is admitted for sinkingthrough valves or openings near the bottom of the pontoon. As thepontoon sinks and the pressure on it increases, the air in the pontoonis compressed and more water enters, increasing the weight on thelowering lines, and together with the surging of the ship at thesurface, setting up strains which are often suflicient to'part thelines.

In addition, the free water surface in the partly filled pontoons allowsthe water to shift causing the pontoons to be unstable and tend to standon one end or the other, thereby throwing added strain on the line atthe low 7 end, and fouling all the lines.

This instability and increasing weight in lowering have made previouspontoon operations difficult, dangerous, and often exceedingly slow; andwhile I have, by closing flood valves on a pontoon about to sink,prevented the entrance of further water while sinking, I have found theoperation very uncertain and dangerous to the man undertaking it.

I have, therefore, designed a stabilized pontoon, which is obtained bydividing the pontoon into compartments of such size, symmetricallydisposed, that when certain of the compartments are flooded, orpractically flooded, and the remainder dry, or practically dry, hepontoon then has the required amount of fixed negative buoyancy, aboutfive tons, to sink it conveniently.

The preferable arrangement of'coinpartments to secure this in acylindrical pontoon is to have more than two compartments, usuallythree. The bulkheads are so spaced that vhen the end compartments, forinstance, are

completely flooded, and the center compartment dry, the pontoon willsink, but cannot get heavier 1n descent, and having no free watersurface in any compartment, either full or empty,it.acts as a fixedweight while being lowered, and concequently avoids the outstandingdefect ofprior pontoons to grow heavier on descent, and to tend to godown one end first. as the free water in the compartments runs from endto. end, making such prior ontoons unstable.

Therefore, in lowering, the pontoon can be given such. small negativeweight, say three to five tons, as permits lowering under easy controlwith moderate sized lines, and there is wholly avoided the necessity ofsuch dangerous practices as closing flood valves before sinking, or thedangers of the pontoon growing. heavier as it descends, or theliabilityof shifting water causing the pentoon to stand on end andthereby tangle itselfin ts lowering lines and guide lines.

' 'ng submarines by ontoons, it is but one end or the other isbound torise first, leaving the other end on the bottom-with the boat at anangle depending on the length of the boat and the depth of water. 'Inthis position, the pontoons assume practically the sameangle as theboatitself and in pontoons, as previously constructed it becomesimpossible to expel all thewater remaining'in the pontoon while at anangle, as the air vents itself from the high discharge valve, leaving awedge of water in the pontoon, wl ich considerably reduces its liftingpower.

It is possible todetermine beforehand which end will be lifted first bygiving that end complete buoyancy in the first part of the blowingoperation. part of my invention, provided a sluice valve, or pipe, witha valve in it, which can be operated from the outside of the pontoonjoining the two end compartments, as will be hercinafter described Myinvention-will be more fully understood after reference totheaccompanying drawings in which Figure l is a. diagrammatic view, showinga sunken submarine with the various pontoons and air lines attached,parts being omitted for the sake of clearness in the drawings.

- Figure 2 is a diagrammatic plan view of the apparatus shown in Figure1.

Figure 3 shows a section along the line 33 of Figure 2', and looking inthe direction of the arrows.

Figure l shovs a section along: the line.

l--l of Figure 2, and looking in the direction of the arrows.

Figure 5 is a plan View, partly broken away, of a: pontoon constructedaccording to my invention.

Figure (l shows central vertical section through the-pentoonshowninFigure-a along.

. e to raise the hoat hoi'izontally,

I have, therefore, as a the broken line 66, and looking in the directionof the arrows.

Figure 7 is an endlview of the pontoon seen from the left of Figure 6.

- F igure 8 shows a section along. the line 88 of Figure 6-, and lookingin the direction of the arrows.

Figure 9 is a diagrammatic View showing two of the pontoons inoperation, and the guide lines leading to the. surface for guiding downanother pontoon not shown.

Figure 10 shows asaddle plate carrying an eye attached to the outer hullof the submarine in the wake of one of-the frames of the vessel.

Figure 11 shows a section along the line l1ll of Figure 10, and lookingin the direction of the arrows.

Figure l2'shows a modified form of p011- toon adapted for use in therapid salvage system herein described.

Figure 13 is an end'view of the pontoon of Figure 12, as seen from theleft of that figure, and

Figure 14 shows a section along the line lt-1l of Figure 12, and lookingin the direction of the arrows.

A represents the outside plating of the hull of the vesselto be raised,which in this particular case is diagrammaticallyshown as a submarine,which vessel is. provided with the usual longitudinal and transverseframes,

one of the longitudinal frames being shown at A in Figures 10 and 11,and one of the transverse frames at A in the said figures. The. hull mayalso be provided with the usual or suitable transverse bulkheads, suchas B in Figure 11, and the usual deck plates C, see FiguresQ and l, andC, see Figure 11.

In other words, I do not propose tomake any changes in the constructionofthe vessel as ordinarily built, except to permanently attach to thevessel fasteningdevices to which the hoisting. wire, chains, or cablesmay be attached, such for instance as the saddle plates D, havingtheeyes D secured to orintegral therewith, as shown diagrammatically. inFigures 1, 3, 4, and 9, and in detail in Figures 10 and 11. Referring toFigures 10 and 11, it willbe seenthat the saddle plates are curved tofit snugly against the deck plating A, to which they are secured bybolts or rivets (Z.

By causing these saddle plates D to register with the transverse framesof the vessel,

as shown in Figure 11, great structural strength is secured and theparts are well adapted to efficiently resist the lifting strainsincident to the operation of floating the sunken vessel.

By having the attaching means in the form of eyes D, as shown in Figure11-, and

placing these eyes well up on the sides of the vessel, preferably abovethe maximum beam, at. that. location, these PIOJBCtlOIlS' will not bematerially in the way; in the ordinary operation of the vessel, such asdocking, going alongside of another vessel, or the like; but at the sametime the combined saddle plates and eyes will not add materially to theweight 5 of the vessel; and thus this permanent addition to thestructure will not materially increase the permanent load carried by thevessel.

This is especially important with submarines where the reserve buoyancyof the vessel is purposely made small, and it is not desirable tomaterially increase the weight carried by the vessel.

Thus in the structure of the submarine or other vessel, the only changenecessary to be made to equip the vessel for salvage according to theimproved system herein described is to add exterior to the watertighthull and as part of the permanent structure a series of attachments towhich the lifting devices may be secured, and for this purpose, thesaddle plates and eyes herein illustrated and described constitute oneform of adequate and efficient attachment.

For use with the eyes and saddle plates just referred to, I providehoisting chains or wires, such for instance as the chains E shown indetail in Figures 6 and 9. These chains areprovided at their lower endswith suitable attaching means, such as the shackles E, see Figure 6,which can be readily connected by the diver to the eyes D, and theirupper ends are attached to the pontoon, as by means of suitable pins, orthe like, E as shown in Figure 6, and as will be hereinafter more fullydescribed.

These chains are lowered from the salvaging vessel (not shown) by meansof lines F indicated in dotted lines in Figure 6 and shown in full linesin Figure 9.

These lines F serve to guide the pontoons down into engaging relationwith the chains E, as will be hereinafter described.

As will be noted later, these chains E are attached to the pontoons, andserve, when the water is blown out of the pontoons, to take the entireweight of the vessel to be salvaged without the assistance of anyderricks, or other hoisting lines from the surface.

Having thus described the construction of the vessels and the liftingchains to be directly connected to the same, I will now procoed todescribe the construction and operation of the pontoons used in theherein desxribed system.

I have shown in Figures 1 to 4 groups of cylindrical pontoons attachedto a vessel to be salvaged, the vessel in Figure 1 being shown restingon the bottom on a substantially even keel; and in Figures 5 to 8, Ihave shown details of one form of cylindrical pontoon especially adaptedfor use in the herein described system; while in Figures 12 to 14, 65 Ihave shown another formof cylindrical pontoon which is adapted to beused with the system described.

Either form of pontoon ust referred to'is suitable for use in the systemshown in Figures 1 to 4, and also in Figure 9.

In this latter figure, I have shown two of the pontoons in section asattached to the vessel, and the guide lines attached to the chains inposition for the lowering of the third pontoon, if such be needed.

In this latter figure, however, it is probable that two pairs ofpontoons will be sufficient to overcome the negative buoyancy of thepartly submerged vessel.

Referring first to the pontoons shown in detail in Figures 5 to 9, Hrepresents a cylindrical shell, having the closed ends it and it, andwith the transverse watertight bulkheads h and it, which separate theinterior of the cylinder into three chambers IP, H and H The centralchamber H is preferably made of shorter axial length than the other twochambers H and H and the chambers H and H are preferably of the samedimensions.

While I have shown, in Figures 5 and (3, the relativeproportions of thechambers, I-I may be relatively larger or smaller than the chambers Hand H but for clearness in the drawings, I have made the central chambersomewhat larger than would ordinarily be required in practice.

Extending vertically through the chambers II and I-I and equidistantfrom the ends of the pontoons are the two hawse pipes H and II, whichare made watertight with the pontoon, as by welding or riveting, or inany convenient way, and which permit the passage therethrough of thelifting chains and guide lines. These hawse pipes H and H are parallelto each other, and cut across the longitudinal axis of the pontoon atright angles thereto, so that these hawse pipes will be centrallylocated relative to the vertical axis of the pontoon.

Thus when the lifting chains are drawn through the hawse pipes, as shownin Figure 6, these chains may be held against withdrawal through thehawse pipes as by suitable locking means, such as the wedges E In. orderto properly control the operation of raising and lowering the heavypontoons, I provide suitable air and water connections to the interiorthereof, which will now be described.

Referring to the construction shown in Figures 5 and 9, and assumingthis construction to be that used in the system illustrateddiagrammatically in Figures 1 to 1-, the end chambers H and H of thepontoon are pro vided with flood pipes I, which may be used for eitherflooding these chambers or drain ing the water out of the same, duringthe blowlng operation. The flood pipesare controlled by valves I, whichare manipulated by-the diver, as willbe'hereinafter described Theseflood pipes are preferably in the form of goose necks bent downward asat i and-nearly touchingthebottom ofthe cham ber.

Opposite the flood pipes, two air vents J and J are provided near theopposite end of the top of the chamber H and siinilarair vents l -and Jare provided at the top and near the end of the chamber H, which arecontrolled by the valves manipulated 'by the diver.

In the central chamber H there are two air vents J and 5 one of which Jis connected by the air hose K to the surface, the other of which 5* isconnected to a telltale pipe L, which projects down into the chamber Hnearly tothe bottom thereof. One of the-airvents J of the end chamber His connected by-the hose K tothesurface. In practice it will bedesirable tohave the pipes K and K as close together as possible, asshown in Figure 6.

The chambers H and H are connected together by a sluice vpipe Mcontrolled by the valve m, which valve on is operated by the valve stemm, which projects up through the top of the pontoon and may bemanipulated by the operator by the use of anyconvenient wrench orhandle.

The chamber is emptied into one of the end chambers bythe bent drainpipe N (see Figure 6),;whioh leads down nearly'to the bottom of:thechamber'I-I as at n, and opens into the chamber H as at a. This drainpipe N is controlled by a valve n having a stem 2, projecting above .thetop of'the pontoon, so thatthe valve a maybe controlled from without thepontoon, by the operator.

For convenience in controlling the pontoon, eyesO and 'O' are providedto which suitable lines (not shown) may be attached.

Assuming the guide lines F to be fed through the empty'hawse pipes ofthe pontoon, and it to be in position .for beginning the operation oflowering, and assuming the guide chains at the end of these haulinglines to be shackled or otherwise fastened tothe eyes D, and assumingthe air hoses Kand K to be attached to the :vents J and J", the centralchamber H will then be filled with air. The end chambers H and H willthen be flooded by opening the valves 1 until the negative buoyancyofthe ,pontoon is sufliciently great; in practice three to .five tons ofnegative buoyancy would be proper for a pontoon h-aving lifting power offorty tons.

lVhen the chamber :H3 is blown, if air comes up through the vent pipe Jit will be known thatthechamber is clear of water; while if water comesup through the pipe, the chamber can be blown until substantially-allthe water-is removed and likewise the flood valves I.

The chambers H H and H are preferably so dimensioned that when the twoend chambers H and are completely filled withwater, and the centralchamber is ,filled with air the pontoon will have the neg :ativebuoyancy necessarylto sink. At this time, there will be little, if any,tendency of either end of the pontoon to tilt up.' i

The end chambers may "be completely filled with water as the pontoonsubmerges by leaving the air vents J, J, J and J open, and likewisetheflood valves I.

The two ends of the pontoon "being thus completely filled with water andempty of air, and the central chamber being filledwith air, the pontoonwillbe stabilized, and there will belittle, if any, tendency of eitherend to tilt up and thus it may be readily controlled as .it 'is lowereddown the guide lines -F until it slips over the chains-E. When the endsof these chains appear above the top of the pontoon, the diver slips inthe wedges, or other suitable locking devices, E and the pontoon issecurely attached to :the chains, and by the chains is securelyattachedto the "vessel to be salvaged.

Now the negative buoyancy of the ,pontoon is changed to positivebuoyancy as follows:

The diver closes ;the vents J, J,,and T the vent (I meantime beingclosed, and opens the valve 02 the valve mbeing closed; then air isapplied under pressure vthrough the hoses K and K.

The .air "hose fK will blow the air from the chamber'H through the drainpipe N, into the chamber H which will'loe emptied through the flood pipeI. Similarly, the air pressure from the hose K will blow water fromthechamber Htout through its flood pipe I. If the water is notsubstantiallycall expelled from the two end chambers 1-1 and 'H due vtoone end of the pontoon being lower than the other when the submarine hasone end already up, then by closing the outlet valve I on the high endof the pontoon and opening the sluice valve m, all the remaining waterwill be forced out ofithe valve I at the low end. This will permit thepipe M to by-pass the liquid from the chambers H to the chamber H if theright end ofthe pontoon be elevated, or the liquid will be dispelled inthe-opposite direction if the left end of the pontoon is tilted.

At this time the pontoon willlbe securely connected to the vessel -.tobe salvaged, and the complete positive buoyancy will aid in lifting thevessel. By having an adequate number of'pontoons, as shown for instancein Figures 1 and 2,'the total required lifting power may be appliedwithout there being plish the desired lifting result; and in Figure 9, Ihave shown two sets of pontoons as prob ably capable of lifting thestern of the vessel therein shown.

By having the eyes D high up on the hull of the vessel, the liftingchains E may be attached to the lower side of the vessel as she lies onthe bottom on her bilges, and the vessel may be rolled to an even keelor beyond, and similar application of pontoons to the other ide may rollthe vessel in the reverse direction; and thus the hull may be loosenedin the mud or ooze at the bottom of the sea, and that suction ordinarilyeX- )erienced in raisin sunken vessels will be in a large measureobviated or minimized.

The foregoing description has set out the operation of the apparatusemploying the three chambered pontoons, as shown in Figures 5 to 9. InFigures 12 to 14 I have shown a pontoon P, having two superposedchambers'P and I separated by the arched partition P The lower chamberis intended to be filled with water through the flood pipes I at eachend thereof, controlled by the valves I.

The upper chamber P is normally filled with air, which is forced inthrough the hose K into either one or the other of the air inlets JShould any water leak into the up- I per chamber this may be blown outthrough the vents J 8 and J I provide vent pipes Q and Q passing throughthe air chamber and Q and Q, near each end of the ontoon so 7 thateither may be used to blow in air, the other being closed, and when itis desired to fill the water chamber with water, either, or both, ofthese vents Q and Q, may be opened, and the water may be allowed to fiowin through the flood pipes I.

The pontoon shown in Figures 12 to 14 is provided with the hawse pipes Hand H for use with the lifting chains, as already fully described withregard to Figures 5 to 9.

In using this form of pontoon, it will be obvious that the air chamberat the top will serve to keep the pontoon in the stabilized position,and that the water chamber can be .completely filled with water, andthus there will be no sloshing around of water in this chamber, and thesame can be controlled like a solid log.

I/Vith this form of pontoon, eyes 0 and 0 may be provided for use ofcontrolling lines.

Any other means may be provided for controlling either form of pontoonherein described.

When preparing for lifting, the end of the submarine to be lifted firstis determined on, and divers then close all the water discharge valveson the ends of the pontoons, which will be high when the first end ofthe submarine lifts, while they open the sluice valves at the same time.

During the lifting operation all water is therefore expelled from thelowest point in the pontoon after it assumes an angle, and no air canvent till the pontoon is practically dry. The total lifting force of thepontoon is thus realized in raising, which has not hitherto been thecase in submersible pontoons.

It is, therefore, possible to use the above system and avoid wholly thefollowing delays which have made submarine salvage sometimes a matter ofweeks and months:

(a) Making watertight and buoyant the undamaged interior compartments,which is a slow and hazardous job for the divers. V

(b) Digging tunnels underneath the boat for slings, which is slow, verydifficult, and extremely dangerous to the divers.

Levelling of and lashing the pontoons before lifting, to prevent themand the slings from slipping off the boat while at an angle duringlifting, which levelling and lashing process is slow and diificult forthe divers.

(cl) Providing additional buoyancy either inside the boat or by extrapontoons, to make up for the unavailable buoyancy of water left in thepontoons as previously built when the pontoons assume an angle duringthe first state of the lifting process; which additional buoyancyhowever provided means much extra work and delay.

The use of the above system of eyes on the boat and of stabilizedsubmersible pontoons makes it possible to secure the necessary liftingpower in sections, one pontoon at a time, and avoids the necessity forhaving more lines running to the surface at any time than are requiredfor handling the pontoon being secured.

lVith this system no lifting lines are required from the submarine tothe surface, whereas in using derricks or surface lifting vessels, ashas been proposed in other nations, a multiplicity of lifting lines mustbe run from the surface to the submarine and attached thereto in somemanner, and it is not possible in deep water and the open sea to keepsuch a mass of lines from fouling each other; moreover, if bad weatherforces a suspension, such lines to surface vessels must be ameopeabuoyed off and will be found a tangled mass when the storm is over.

)n the other hand, with the system I propose, each pontoon when-securedto thesunlren vessel is a finished job, no lines to the-surface arethereafter required; and if a storm comes along, operations can besuspended with no lines to the surface to be buoyed off, andconsequently work can be resumed promptly when conditions permit.

The only lines to the surface required for lifting are the air hoses;these can always be buoyed oil, and if they fouleach other, it is amatter of no moment and they do not require to be cleared thereafter.

The salvage system here proposed makes it .possible to lower and securepontoons at the rate of one per hour; making allowances forinterruptions, night work, etc, a properly equipped diving ship canlower and secure twelve pontoons in less than two working days and raisea thousand ton submarine immediately thereafter, making it possible torescue the crew if still .alive, and to salvage the boat at triflingexpense compared to the present methods which require months of work.

While I have described the system andapparatus especially designedtherefor, it will be obvious .that changes might be made in theconstruction, combination, and arrangement of parts, which could be usedwithout departing from the spirit of my invention, and I do not mean tolimit the invention to such details except as particularly pointed outin the claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent of the United States is .1. A rapid salvage system forraising sunken vessels substantially by buoyancy alone, comprising aseries of chain attaching devices permanently secured to the exterior ofthe watertight hullv of the vessel, a series of submersible horizontallystabilized pontoons each including a central air chamber having nodirect inlet to the outer "water, whereby the volume of water admittedto the remaining portions of the pontoons constitutes the entireeffective liquid weight in submerging and each provided withh-awse pipesnear each end thereof, and lifting chains passing through said pipes andattached near the upper ends to the pontoon above said pipes, and attheir lower ends to said attaching devices.

2. A rapid salvage system for raising sunken vessels substantially bybuoyancy alone, comprising a series of chain attaching devicespermanently secured to the exterior of the watertight hull of thevessel, in the wake of transverse frames of the vessel, a-seriesofsubmersible horizontally stabilized pontoons each including a-cen'tra-lair chamber having no direct inlet to-the outer water, whereby thevolume of water zadmittedito the remaining portions of the pontoonsconstitutes the en- .tireeffective liquid weight in zsubmergingand eachprovided with .hawse pipes near each end thereof, and lifting chainspassing through of water admitted to the remaining portions. of' thePIQ'OIYILZOOHS constitutes the entire eifective liquid weight insubmerging and each provided with hawse pipes .near :each end thereof,:and lifting chains passing through said pipes and attached near theupper ends to the pontoon above said {pipes and at their lower ends topairs of'saideyes.

4. A rapid salvage system for raising sunken vessels substantially bybuoyancy alone, comprising a series of=chain attaching devicespermanently secured to the exterior of the watertight :hull of thevessel, a series of submersible horizontally stabilized pontoons eachincluding a central air chamber having no 'direc-t inlet to the outerwater, whereby the volume of water admitted .to the remaining portionsof the :pontotons constitutes the entire effective liquid weight in sub1 said pipes and attached near the upper ends 7 to the pontoon abovesaidpipes and .ratztheir merging and each provided with ihawse pipesnear-each end thereof, and lifting chains passthrough said pipes andattached near the upper aends to the pontoon above said pipes, and at(their lower ends 'to-said attaching devices, and guide lines secured tothe upper ends :of said lifting chains, and adapted to be rovethroughsaid pipes,.and to lead above the surface of the water.

5. A rapid salvage system for raising sunken vessels substantially bybuoyancy alone,

comprising-a-series of chain attaching devices permanentlysecured to theexterior of the watertight hull of the vesselyin the Wake of transverseframes of the vessel, a series of submersible horizontally stabilizedpontoons each including acent-ral air chamber having no direct inlet tothe outer water, whereby the volume of water admitted to the remain ingportions of the pontoons constitutes "the entireeffective liquid weightin .submerging and each provided with hawse pipes near each end.the-reof,-and lifting chains passing through said pipes and attachednear the uppe'r-ends-to the pontoon above said pipes and at their lowerends to said attaching devices, and guide lines se'cusred to the upperends of said lifting chains, and adapted to be rove through said pipes,and to lead above the surface of the Water:

6. A rapid salvage system for raising sunken vessels substantially bybuoyancy alone, comprising a series of saddle plates permanently securedto the exterior of the watertight hull of the vessel, in the wake oftransverse frames of the vessel with eyes carried by said saddle plates,a series of submersible horizontally stabilized pontoons each includinga central air chamber having no direct inlet to the outer water, wherebythe volume of water admitted to the remaining portions of the pontoonsconstitutes the entire effective liquid weight in submerging and eachprovided with hawse pipes near each end thereof, and lifting chainspassing through said pipes and attached near the upper ends to thepontoon above said pipes and at their lower ends to pairs of said eyes,and guide lines secured to the upper ends of said lifting chains, andadapted to be rove through said pipes, and to lead above the surface ofthe water.

7. A rapid salvage system for raising sunken vessels substantially bybuoyancy alone, comprising aseries of eyes permanently secured to theexterior of the hull of the vessel, a series of submersible horizontallystabilized pontoons each including a central air chamber having nodirect inlet to the outer water, whereby the volume of water admitted tothe remaining portions of the pontoons constitutes the entire effectiveliquid weight in submerging and each provided with a pair of verticallydisposed chain pipes passing therethrough near the ends thereof, andlifting chains attached near the upper ends to the pontoon above thechain pipes, and at their lower ends to said eyes, with means forlowering said pontoons into the attached position, and for thenexpelling the water from said pontoons.

8. A rapid salvage system for raising sunken vessels, comprising aseries of saddle plates permanently secured to the exterior of the hullof the vessel, each plate registering with a transverse frame of thevessel, each saddle plate being provided with an eye for attaching achain thereto, a series of horizontally stabilized pontoons eachincluding a central air chamber having no direct inlet to the outerwater, whereby the volume of water admitted to the remaining portions ofthe pontoons constitutes the entire effective liquid weight insubmerging and each pro vided with a pair of vertically disposed chainpipes passing therethrough near the ends thereof, and ].i ting chainsattached near the upper ends to the pontoon above the chain pipes, andat their lower ends to said eyes, with means for lowering said pontoonsinto the attached position, and for then expelling the water from saidpontoons.

9. In a rapid salvage system for raising sunken vessels, a horizontallystabilized pontoon, comprising a cylindrical shell with bulkheadsdividing the same into a central air chamber having no directcommunication with the outside water, and symmetrically disposed endchambers separate therefrom, means for filling said end chambers withwater, means for lowering the pontoon and attaching same to the sunkenvessel, the volume of water admitted to the end chambers constitutingthe entire liquid effective weight in submerging, and means for thenblowing the water from the end chambers by air under pressure, wherebythe pontoon is rendered buoyant and tends to lift the sunken vessel.

10. In a rapid salvage system for raising sunken vessels, a horizontallystabilized pontoon, comprising a cylindrical shell with bulkheadsdividing the same into a central air chamber having no directcommunication with the outside water, and symmetrically disposed endchambers separate therefrom, with a pipe projecting vertically througheach of said end chambers, means for filling said end chambers withwater, means for lowering the pontoon and attaching same to the sunkenvessel, the volume of Water admitted to the end chambers constitutingthe entire liquid effective weight in submerging comprising guide linesand lifting chains rove through said hawse pipes, and means for thenblowing the water from the end chambers by air under pressure, wherebythe pontoon is rendered buoyant and tends to lift the sunken vessel.

11. In a rapid salvage system for raising sunken vessels, a horizontallystabilized pontoon, comprising a cylindrical shell with bulkheadsdividing the same into a central air chamber having no directcommunication with the outside water, and symmetrically disposed endchambers separate therefrom,

means for completely filling said end chambers with water, comprisinginlet valves at the lower outer corner of each end chamber, and a sluicepipe passing through said central chamber, and opening into each endchamber. and a valve operable from the exterior of the pontoon forclosing said sluice pipe, when desired, means for lowering the pontoonand attaching same to the sunken vessel, and means for then expellingthe wa ter from the end chambers, whereby the pontoon is renderedbuoyant, and tends to lift the sunken vessel.

12. In a rapid salvage system for raising sunken vessels, a horizontallystabilized pontoon, comprising a cylindrical shell with bulk headsdividing the same into a central air chamber, and symmetrically disposedend chambers separate therefrom, means for filling said end chamberswith water, means for lowering the pontoon and attaching same to thesunken vessel, and means for then expelling the water from the endchambers,

whereby the pontoon is rendered buoyant and tends to lift the sunkenvessel, said water expelling means comprising air hoses connected,respectively, to said central chamber, and to one of said end chambers,a pipe connecting said central chamber with the other end chamber, avalve operable from the outside of the pontoon for opening and closingsaid pipe, a sluice pipe connecting the lower corners of said outerchambers adjacent said inner chamber, with a valve controllable from theexterior of the pontoon for opening and closing said sluice pipe, anddrain locks at the outer lower corners of said outer chambers.

EDWARD ELLSBERG.

